Variable Rate Multi-Mode Wideband (VMR-WB)

The Variable Rate Multi-Mode Wideband (VMR-WB) codec was standardized by 3GPP2 for cdma2000® wideband telephony and multimedia streaming services and is supported in the CableLabs® PacketCable™ 2.0 specification. Designed by Nokia and VoiceAge, VMR-WB is based on the AMR-WB/G.722.2 codec and includes one mode of operation that is interoperable with it.

VMR-WB operates in four modes in Rate-Set II and one mode in Rate-Set I. Modes 0 to 3 operate in Rate-Set II. Modes 0, 1, and 2 are specific to CDMA systems (i.e., TIA/EIA/IS-95, cdma2000), with mode 0 providing the highest quality and mode 2 the lowest average data rate (ADR). Mode 3 is interoperable with AMR-WB/G.722.2 at 12.65 kbps and below. Mode 4 is compliant with Rate-Set I, with an ADR slightly lower than mode 2 and equivalent or better quality.